On track, until the winter of 2014, when as it always does, the petri dish of germs, otherwise known as “preschool”, claimed its first victim.

This is what I get when I listen to this video, I could hear it wrong, it may not be "preschool" at all. Here is the link to the video, it appears at 1:40

This sentence describes a four-year-old having a strep throat. I understand the other parts of the sentence but can't get my head around this "otherwise known as 'preschool' here. Why would they call a petri dish of germs "preschool"?

  • 11
    Compare " ... gladiatorial blood sport, otherwise known as American football". It's intended to be a kind of jaded witticism.
    – TimR
    Commented Jan 13 at 11:01
  • 2
    AKA kindergarten AKA daycare AKA the virus factory. Commented Jan 15 at 23:03

2 Answers 2


It's the other way round - she is calling 'preschool' (nursery school) a 'Petri dish of germs' because infections often spread rapidly among a group of children from different families who are too young to have developed much immunity.

This is a humorous way of making a comparison more striking. Instead of saying 'Preschools are like a Petri dish full of germs', the speaker starts with the comparison and then goes on to explain 'I mean preschools'.

  • 19
    Lack of acquired immunity is one factor. Another is small children's habit of putting everything in their immediate environment into their mouths.
    – Kirt
    Commented Jan 14 at 2:21
  • 2
    @Kirt: And the lack of concern of caregivers about hygiene.
    – user21820
    Commented Jan 15 at 8:33
  • 12
    It would be useful to explain more about this inverted type of metaphor, as it's a common rhetorical device that ELLers should become familiar with.
    – Barmar
    Commented Jan 15 at 15:47
  • 1
    @Kirt universities are also considered petri dishes of germs and students should be mature enough not to put everything in their mout... oh never mind
    – MD-Tech
    Commented Jan 16 at 14:34

As per the comment by @Barmar, here my attempt at a more meta-explanation.

It is a joke. Not a classical joke with a punchline but the bait-and switch kind of joke. You first create a image in the head of the reader (petri dishes are used in laboratories, by people in white coats, to do experiments) but then the writer clarifies themselves: it is not a lab, it is actually a preschool! The intent here is that some of the imagery from the first word carries over to the second clarification: toddlers can be studied by people in white coats for the new and exciting bacteria they carry.

There are a few ways this joke is done. The "otherwise known as" is a very classical setup. There is also a form where the writer pretends to be confused themselves, sometimes apologizing with a "the petri dish, sorry I meant the preschool".

It is a kind of metaphor, where X is compared to Y, to clarify something about either.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .